Work on the molecular characterization of the Na,K-ATPase and the reconstituted transport of Na ion and K ion in liposomes containing the purified shark rectal gland enzyme will be continued. Studies on the biosynthesis of the enzyme in isolated electroplax tissue and in electroplax in vivo will be continued, utilizing (3H) valine pulses, minipurification of the enzyme, isolation of the subunits on SDS-polyacrylamide gels, precipitation of nascent subunits with antibodies, and differential centrifugation and gradient centrifugation. The role of phospholipids in the reconstituted pump will be studied with phospholipids with well-defined fatty acid composition and varying head-groups. The factors responsible for the potential difference across the vesicle will be further investigated to determine whether the potential is exclusively an electrogenic potential or a composite of an electrogenic potential and Nernst potentials. The effects of wheat germ agglutinin on the coupled transports of Na ion and K ion in vesicles and the possible reversal by specific sugars will be studied. The effects of wheat germ agglutinin on the Na,K-ATPase and the reconstituted transports will be correlated under various conditions. BIBLIOGRAPHIC REFERENCES: Ratanabanangkoon, K., Blaiklock, R. and Hokin, L. An Improved Synthesis of N-(2,3-3H) (n-propyl)-hydroxylamine, a Potentially Useful Reagent for the Characterization of Acyl Derivatives. Analytical Biochemistry, 77, 567-568 (1977). Hokin, L.E. (1977) in Biochemistry of Membrane Transport (Semenza, G. and Carafoli, E., eds.) FEBS Symposium No. 42, pp. 374-388, Springer-Verlag Berlin Heidelberg, New York.